[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: Stretch, Radeon 4850, and backlight



On Thu, 2016-06-23 at 20:36 +0200, Sven Arvidsson wrote:
On Thu, 2016-06-23 at 10:42 -0600, James Lay wrote:
Hey all, so....I have an oldish iMac 24 inch.  It comes with a Radeon Mobility HD 4850.  After install of Stretch testing, this worked fine, save for one small issue of the backlight not going out.  As I run this as kind of a server with no need to see the screen most of the time, I'd like to get the backlight to go out.  So I installed firmware-linux- nonfree.   This actually causes me to get a blank screen...just the backlight on.  I can ssh into the machine, but I get no screen at all (http://askub un tu.com/questions/688388/14-04-gets-black-screen-unless-radeon- modeset-0 ).  I DO however see the backlight go out.  Right now I'm using radeon.modeset=0 to get an active screen again.  My question is there any way I can troubleshoot getting the backlight to go out?  I've got to:
I found some old reports about video output being redirected to the external display, that might be something to investigate? You don't run X at all? If so I'm not quite sure of to check for which display is active or how to control backlight.

Thanks for the quick response.  This currently is running X, but only with radeon.modeset=0 for kernel args.  Otherwise, the machine boots, just black screen.



Reply to: